Tobacco use is the second leading risk factor for death, estimated to be responsible for 9% of all deaths worldwide. The degree of harm (i.e., rates of death and disease) to the population due to use of tobacco products is dependent on both magnitude of use (prevalence and intensity of product use) and toxicity of the products used. To determine how the introduction of new tobacco products would affect population harm, we need more sensitive and comprehensive procedures for abuse liability assessment, including the likelihood that a new tobacco product will be used in place of, or together with, conventional tobacco products such as cigarettes. Current methods of abuse liability assessment of drugs developed over several decades have been shown to have excellent external and predictive validity. However, accurate assessment of the abuse liability of tobacco products will require greater sensitivity to (1) detect differences between the increasing number of similar products, (2) acknowledge and incorporate environmental and situational factors that can affect the likelihood or magnitude of use, and (3) provide the ability to distinguish between products that might be used together compared to those that might substitute for each other. In Project 2, we aim to apply a behavioral economic approach to the development of more sensitive and comprehensive abuse liability assessment methods for tobacco products. Specifically, we will use these behavioral economic methods of abuse liability assessment across three platforms or approaches that vary in cost, and effort (e.g., human laboratory, ecological assessment, and questionnaire). Modified abuse liability methodology that incorporates behavioral economic analyses is expected to lead to more accurate assessments of potential population harm from the possible introduction of new products and the avoidance of past mistakes. Specifically, in Specific Aim 1, we will compare the demand function for a potential modified-risk tobacco product, Camel snus (oral, spit-less tobacco pouches), to demand functions for conventional cigarettes (positive control for an abused substance) and for medicinal nicotine (negative control for a low abuse liability safer product) across a range of prices in the laboratory setting, on an outpatient basis, and using questionnaire-based methods. In Aim 2, we will investigate product choice across a range of prices in each of these platforms. In Aim 3, we will examine how changing the price of cigarettes might affect the consumption of alternative products in each of the same settings. In Aim 4, across all the studies we will compare the three assessment procedures and three platforms in terms of (1) rendering the same assessment, cost of assessment and prediction of the clinical trial proposed in Project 4. In light of recent legislation giving FDA broad regulatory authority over tobacco products, these studies will provide timely and much needed information regarding the methods to use to assess the likelihood of initiation and continued use of these products, which have the potential to impact public health. Moreover, the development of more sensitive abuse liability methodology as proposed in this application has the potential to define the standards by which abuse liability assessment of modified-risk tobacco products is conducted.